The present invention relates generally to underground bore location systems and, more particularly, to a novel underground bore location system and method for detecting and compiling bore location data so that a bore map may be generated.
Those of ordinary skill in the art should recognize that the term xe2x80x9cborexe2x80x9d refers to the excavation of a hole, typically for utilities, through the ground and to the excavated hole itself. The present invention relates to systems and methods for locating such bores, but also to such systems and methods for locating existing buried utilities, whether such existing utilities were initially installed by boring or trenching techniques. Accordingly, unless otherwise indicated, the term xe2x80x9cborexe2x80x9d as used herein refers to new bores and to existing buried utilities or similar lines.
Boring location systems are utilized in a variety of circumstances. For example, in horizontal boring systems as are typically used for installing utilities, it is desirable to maintain a directional boring head in a desired boring path and to avoid known obstacles such as existing utilities. Accordingly, systems are known to trace existing utilities from an aboveground position. Similarly, it is often desirable to map existing utilities.
While such known systems are capable of indicating the position and depth of a bore at a specific location, they are generally unable to produce a corresponding plot during a new bore or as an existing bore is located. Such plots may, for example, track the position of a new bore with respect to known underground obstacles. Thus, an operator may, by monitoring the plot, control the directional boring head to avoid the obstacles. Such mapping of a new or existing bore has in the past been accomplished manually. For example, an operator with an aboveground monitoring device that detects a signal radiated from a probe proximate a directional boring head may walk on the ground surface tracing the progress of the probe during the bore. The operator may manually relay information to a second operator by voice or other communication means so that a plot of the bore may be generated.
Manual plotting methods are slow, inefficient, and prone to error. Thus, it is desirable for a bore location system to automatically compile data relating to the depth of a bore so that a bore plot may be automatically generated.
The present invention recognizes and addresses the disadvantages of the prior art. Accordingly, it is an object of the present invention to provide an improved bore location system.
It is a further object of the present invention to provide a system and method for mapping a horizontal bore which determines the position of the bore through detection of electromagnetic signals radiated from the bore.
It is a still further object of the present invention to provide a system and method for producing bore plot information in real time as a bore is located.
These and other objects are achieved by providing a system for mapping horizontal bores below a ground surface. The system includes a transmitting source configured to radiate a location signal from the bore. A receiver device is configured to receive the location signal and to indicate, responsively to the location signal, the lateral position of the horizontal bore with respect to the receiver. A measurement device is configured to measure the depth of the bore with respect to the ground surface at selected locations along the bore, and a monitor device is configured to receive depth data from the measurement device. The monitor device is also configured to compile the depth data associated with the selected locations with respect to at least one reference position and to output the compiled depth data so that the depth of the bore at the selected locations may be collectively identified.
The measurement device may be configured to measure the underground depth of the bore by a variety of methods. For example, depth measurements may be taken by determination of a field gradient of a received location signal or by detection of a radiated magnetic field indicating deviation from a predetermined desired path. Furthermore, the measurement device may be embodied by the receiver device. Accordingly, in one presently preferred embodiment, the receiver device and measurement device comprise a single portable assembly which the operator uses to locate the lateral position of the bore via the location signal, taking a depth measurement in a known fashion at the selected location. Thus, a visual display device at the receiver may display information indicative of both the bore""s lateral position and depth.
Similarly, the transmitting source may generate the location signal in a number of ways. For example, the source may be a probe fed through an existing bore or housed within a boring head cutting a new bore. Alternatively, the source may be an aboveground unit that directly creates or indirectly induces an electric current along an existing utility which, in turn, generates a radiating magnetic field which is received by the receiver device. Furthermore, the source may be the utility itself where the utility conducts an electric current that generates its own magnetic field.
A method according to the present invention for mapping horizontal bores below a ground surface includes the steps of receiving a location signal radiated from the bore, determining depth of the bore responsively to the received location signal, compiling data corresponding to the depth of the bore at selected locations along the bore, and displaying the compiled data so that the depth of the bore at the selected locations may be collectively identified.